Cabinets and furniture manufactured today in the U.S. for hospitals and medical facilities, business offices, laboratories, many other commercial entities, and increasingly residential kitchens, are often made in the frameless style. These cabinets are simply boxes made from flat panel material such as edgebanded melamine faced particleboard, high pressure laminate faced particle board, or from hardwood plywood. Doors and drawer fronts essentially hide the front edges of the cabinet boxes. No face frame is needed. Mounting plates for concealed hinges are attached directly to the inside of the cabinet side panels along with drawer slide hardware and adjustable shelf supports.
Much of the above mentioned hardware is designed to be mounted with special screws or pins which fit into 5 mm diameter holes. These holes are drilled in columns parallel to the front edge of the cabinet side panels and rows parallel to the top edge. The centerline of the first column of holes is typically at a standard distance of 37 mm from the front edge of the cabinet side panel with an additional column of holes drilled near the back of the cabinet at a multiple of 32 mm back from the first column for the rear most mounting screw in the drawer slide and or for the rear shelf support. Intermediate columns of holes are sometimes drilled, again at multiples of 32 mm, between the front and rear columns for additional drawer slide mounting screws. Within each column, holes are spaced at 32 mm or multiples of 32 mm above or below one another beginning at a standard distance from the top edge of the cabinet panel.
In larger cabinet shops or furniture factories these 5 mm hardware mounting holes are often drilled on large expensive multi spindle drill machines or on even more large and expensive computer controlled panel processing machines and point to point drilling machines. A great deal of floor space and capital investment are required. Smaller commercial cabinet shops and home workshops with limited space and budget have available to them a wide variety of templates, drill guides, and jigs used with hand drills or plunge routers. In addition, small multi spindle drill heads for use with drill presses are available to aid in drilling the holes used in cabinet construction.
Unfortunately these jigs, templates etc. are sometimes inaccurate in locating holes, slow to set up, often locate and drill only a small number of holes per set up, require substantial time resetting for subsequent columns or rows of holes. Some systems require considerable effort and accumulated time to lift a router off a template or a drill from a guide bushing then reinserting it for each hole to be drilled. With some systems it is necessary to measure and mark reference points or center lines on the panels. U.S. Pat. No. 6,524,033 B1 shows a complex system, wherein a bench, several templates, multiple registration pins etc. are required along with the router equipped with it's guide bushing. A system marketed by “Festool” as the LR32 hole drilling set uses a guide rail which gets clamped to the panel. It has adjustable gauging bars with slidable stops which register off the front edge of the panel to locate the first column of holes at 37 mm. Some calculations are required and readjustment of the slidable stops to reposition the guide rail from the back edge and reclamping so that a back column and or an intermediate column of holes can be drilled. The system uses a plunge router with attached guide plate which has a movable pin which drops into holes in the guide rail to hold the router in position while a hole is drilled. It is necessary to manually lift the registration pin from the hole in the guide rail then move the router forward while holding registration pin up until the next selected hole position is reached. Another patent, U.S. Pat. No. 5,056,966 uses a complex arrangement of rails clamping bars and gauges to position a drill guide bushing to locate a portable drill. Unfortunately portable drills tend to produce imperfect holes with chipped edges or torn veneer. U.S. Pat. No. 5,560,408 uses a clamp on template and a plunge router with a guide bushing to drill columns of holes for shelf supports but would not work well to drill holes at specific spacings to fit the screw holes in the front and back ends of drawer slides. U.S. Pat. No. 5,217,331 likewise designed to drill holes for shelf supports would not work well for drawer slide screws. Productivity issues and the appearance and precision of the holes are a real concern. Consider that a small kitchen with 12 to 15 cabinets would have 24 to 30 side panels requiring holes for hardware items that may include drawer slides, hinges, and shelf supports. The total could easily reach 1000 to 1500 holes. Drilling with an inefficient system requiring frequent resetting or repositioning of jigs or fixtures, and or the lifting of a plunge router or hand drill and realigning and reinserting of a bit or guide bushing into a template or drill guide for each hole would be extremely tedious.
Generally the systems described here as prior art are not best suited for the uniform high quality production drilling required in a small commercial shop.